Basic types of Java Basic Learning

There are 8 basic types of Java

Integer type:
Byte (1 bytes or 8 bits)
Short (2 bytes or 16 bits)
Int (default integer type) (4 bytes or 32 bits)
Long (8 bytes or 64 bits), when the value of a long is expressed, the value must end with L or L
Floating-point types:
Float (4 bytes or 32 bits), when representing a value of float, you need to add F or f at the end of the value
Double Default (8 bytes is 64 bits)
Char type: (2 bytes or 16 bits)

In Unicode encoding format, its essence is still an integer

Boolean type:
True (1 bytes or 8 bits)
False default (1 bytes is 8 bits)

Type name	BYTE space	Scope of Use
Byte	1 bytes (8 bits)	-27~27-1 is mainly used for storing byte data, more commonly
Short	2 bytes (16 bits)	-215~215-1 rarely used
Int	4 bytes (32 bits)	-231~231-1 default, storing ordinary integers, most commonly used
Long	8 bytes (64 bits)	-263~263-1 long integers, which are more commonly used when int cannot be stored
Float	4 bytes (32 bits)	Storing single-precision floating-point numbers
Double	8 bytes (64 bits)	Store double-precision floating-point numbers, commonly used
Char	2 bytes (16 bits)	0~65535 Store a character commonly used
Boolean	1 bytes (8 bits)	Store logical variables (true, false) common

Commonly used escape characters

　　

The above basic types are from small to large: Byte-short-int (char)-long-float-double

1) from small type to large type, automatic type conversion can be done
2) from large type to small type, forced type conversion is required, but precision is lost

　　

        byteB1 = 10;//integers can be assigned directly in this range, and when the operation is required, it is actually converting B1 to int before the operation         ShortS1 = 20;//integers can be assigned directly in this range, and when the operation is required, it is actually converting B1 to int before the operation        intI1 = 30; I1=S1; S1= I1;//compilation requires a forced type conversionS1 = ( Short) I1; LongL = 40L;//At this point 40 is a long type, in order to clearly indicate in the post plus L                floatF1 = 3.45;//Compile Error        floatF2 = 3.45F; DoubleD1 = 4.4; DoubleD2 = 2; System.out.println (D1-D2);//output is 2.4000000000000004 double type is non-precision operation                CharC1 = 65;//char type is an integer typeSystem.out.println (C1); C1= 97;                SYSTEM.OUT.PRINTLN (C1); BooleanBOOL =true; BooleanBool2 =false;

Basic types of Java Basic Learning